Approximately 0.6% of the volunteer donor population has been found to have antibody to the hepatitis C virus (anti-HCV), the predominant cause of transfusion associated hepatitis (TAH). Some of these donors are true positive as determined by a recombinant immunoblot assay (RIBA) and some are false positives and some are RIBA indeterminate. This study will enroll 100 anti-HCV positive donors in each of the RIBA categories and compare epidemiologic risk factors for HCV acquisition and the extent of associated liver disease. Preliminary analysis reveals that at least 60% of RIBA positive donors have recognized parenteral risk factors, primarily IV drug use, compared to less than 5% of controls. These risk factors should have excluded these individuals from donation, but failed to do so indicating the need for revision of donor screening procedures. A large number of asymptomatic RIBA positive donors have biochemical evidence of chronic hepatitis.